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KR-20260062473-A - A PAPER SENSOR AND METHOD FOR FABRICATION OF A PAPER SENSOR FOR DIAGNOSING ENVIRONMENTAL DISORDERS

KR20260062473AKR 20260062473 AKR20260062473 AKR 20260062473AKR-20260062473-A

Abstract

A diagnostic paper sensor and a method for manufacturing a diagnostic paper sensor are provided. The above method for manufacturing a diagnostic paper sensor comprises: a pattern design step in which, when a rectangular paper is provided, the rectangular paper is divided into equal intervals along the long axis direction using origami lines, and each divided area is formed in order of a sample load section, a ninhydrin section, a sensing section, and a waterproof section, and a cutting area is set; a separation step in which the set cutting area is separated from the paper through cutting; a ninhydrin application step in which a ninhydrin solution is applied to a first cutting section separated from the sample load section and a second cutting section separated from the ninhydrin section among the separated cutting areas; and a PDMS (Polydimetylsiloxane) coating step in which a non-cutting area excluding the cutting area is coated with a PDMS (Polydimetylsiloxane) solution.

Inventors

  • 최영수

Assignees

  • 광주대학교산학협력단

Dates

Publication Date
20260507
Application Date
20241029

Claims (9)

  1. A pattern design step in which, when a rectangular paper is prepared, the rectangular paper is divided into equal intervals along the major axis using origami lines, a sample load section, a ninhydrin section, a sensing section, and a waterproof section are formed in sequence for each divided area, and a cutting area is set; A separation step of separating the set cutting area from the above rectangular paper through cutting; A ninhydrin application step of applying a ninhydrin solution to a first cutting section separated from the sample load section and a second cutting section separated from the ninhydrin section among the separated cutting regions; A PDMS coating step of forming a PDMS coating layer by coating the non-cutting area, excluding the above-mentioned cutting area, with a PDMS (Polydimetylsiloxane) solution; A bonding step of bonding the first cutting portion to the PDMS-coated non-cutting area, bonding the second cutting portion to the PDMS-coated non-cutting area, and bonding the third cutting portion separated from the sensing portion to the PDMS-coated non-cutting area; A plasma treatment step of treating the upper and lower parts of the assembly with O2 plasma, wherein the bonded non-cutting area, the first cutting part, the second cutting part, and the third cutting part are defined as an assembly; and A multilayer structure forming step comprising folding the plasma-treated assembly along the origami lines to form a multilayer structure; Method for manufacturing a diagnostic paper sensor.
  2. In paragraph 1, After the above multilayer structure formation step, The method further includes a heating step of heating the PDMS coating layer by heat-treating each layer of the assembly having the above multilayer structure, and The heating step above forms a sealed structure without a separate adhesive by bonding the PDMS (Polydimetylsiloxane) coating layers together through heating. Method for manufacturing a diagnostic paper sensor.
  3. In paragraph 2, The above PDMS coating step is, The method includes the step of coating the surface of the non-cutting area by applying a PDMS solution using the water-repellent properties of the PDMS. The above plasma treatment step is, OH- (hydroxyl) functional groups are generated on the surface of the surface coated with the above PDMS through O2 plasma treatment, and Characterized by strengthening the chemical bond between the PDMS and the surface to increase adhesion, Method for manufacturing a diagnostic paper sensor.
  4. In paragraph 1, The above rectangular paper is Whatman paper made of a porous material so as to be loaded with a measurement sample, The above PDMS coating utilizes water-repellent properties to prevent the measurement sample from being damaged or contaminated by the external environment. Method for manufacturing a diagnostic paper sensor.
  5. In paragraph 1, The above separation step separates the first cutting section from the sample load section, separates the second cutting section from the ninhydrin section, and separates the third cutting section from the sensing section, and The above adhesive step involves inserting the first cutting portion into the first hole created in the sample load portion through cutting and adhesively bonding it. The above second cutting part is inserted into the second hole created in the ninhydrin part through cutting and adhered, Inserting the above-mentioned third cutting part into the third hole created in the above-mentioned sensing part through cutting and bonding it. Method for manufacturing a diagnostic paper sensor.
  6. In paragraph 1, The above multilayer structure formation step is, A stacked structure is formed by folding in a clockwise or counterclockwise direction so that adjacent surfaces come into contact along the above origami folding line, and At one end of the above-formed laminated structure, at least one of one end of the third cutting part, the first cutting part, and the second cutting part is formed coaxially. Method for manufacturing a diagnostic paper sensor.
  7. In paragraph 1, The above ninhydrin application step is, After applying the ninhydrin solution to the cutting area, drying at a temperature below a preset temperature so that a high concentration of the ninhydrin solution is uniformly applied to the cutting area. Method for manufacturing a diagnostic paper sensor.
  8. A sample load portion coated with PDMS (Polydimetylsiloxane) solution is provided, and A ninhydrin portion coated with a PDMS solution is provided, and A sensing part coated with PDMS solution is provided, and The ninhydrin portion is laminated beneath the sample load portion, and The sensing part is stacked underneath the above ninhydrin part, and The sensing part is formed such that one end protrudes from the ninhydrin part while stacked beneath the ninhydrin part, and A first cutting section coated with a ninhydrin solution is formed in the center of the above sample load section, and A second cutting portion coated with a ninhydrin solution is formed at a position that overlaps and contacts the first cutting portion in the above ninhydrin portion, and A third cutting portion is formed in the above sensing portion, which is not coated with PDMS (Polydimetylsiloxane) solution and is not coated with Ninhydrin solution, and When one end of the sensing part protruding from the ninhydrin part while laminated to the ninhydrin part is defined as a protruding portion, The third cutting portion includes a mixing channel formed at a position that overlaps and contacts the second cutting portion and extends toward the protruding portion, and The third cutting part is connected to the mixing channel and includes a sensing area formed on the protruding part, The first cutting section, the second cutting section, and the mixing channel, which are superimposed on each other, form a vertical fluid channel such that a measurement sample loaded in the sample loading section propagates sequentially along the sample loading section, the ninhydrin section, and the sensing section, and The measurement sample propagated to the sensing unit along the vertical fluid channel propagates to the sensing area along the mixing channel, Diagnostic paper sensor.
  9. A first layer including a sample load section; A second layer located below the first layer and containing a ninhydrin portion; A third layer located below the second layer and including a sensing unit; and A fourth layer located below the third layer and including a waterproof portion; comprising, The sample loading section, the ninhydrin section, and the sensing section are connected through a vertical fluid channel, and When a measurement sample is loaded into the sample load section above, The measurement sample is uniformly moved to the sensing unit through the vertical fluid channel, and a diagnosis of the measurement sample, including proline concentration analysis, is performed. The lengths of the first layer and the second layer are formed to be shorter than the third layer so as not to cover the sensing part, Diagnostic paper sensor.

Description

A paper sensor for diagnosing environmental disorders and a method for manufacturing the same The present invention relates to a diagnostic paper sensor, and more specifically, to a diagnostic paper sensor for environmental disorders with reduced sample loss and a method for manufacturing the same. Due to their inherent immobility, crops and plants are significantly affected by various environmental factors during their growth. In particular, among these factors, environmental disturbances such as drought, high temperatures, high salinity, heavy metals, cold damage, and ozone cause stress to crops or plants, placing significant limitations on their growth and development. These environmental disturbances disrupt metabolic processes essential for plant growth and can ultimately lead to problems such as reduced crop yields. Crops exhibit various physiological and biochemical responses to cope with diverse stresses during their growth process, and among these, the amino acid proline acts as an important biomarker. Proline is a secondary amine known as an environmental amino acid possessing an alpha-amino group, and its concentration increases when plants are subjected to environmental stress. Beyond its role as a mere amino acid, proline functions as a signaling molecule within plants. In other words, crops facing environmental disturbances such as drought accumulate proline in their cytoplasm. The accumulation of proline significantly influences various physiological processes within plants, including protein synthesis, photosynthetic efficiency, flowering time, and endosperm development. Therefore, the degree of environmental stress experienced by crops can be quantitatively measured through changes in proline concentration. Such analyses are typically conducted in laboratories, which presents a limitation as they cannot be performed directly in the field. Collecting crop samples, transporting them to a laboratory, and analyzing them takes a significant amount of time, making it difficult to obtain immediate feedback on crop growth status. For example, farmers or researchers may struggle with making decisions regarding growth management because they cannot monitor crop environmental stress in real time. To address these issues, technology capable of rapid and accurate measurements in the field is essential. To improve these drawbacks, a "paper-based multilayer structure sensor" capable of detecting proline in the field was developed and registered as Patent No. 10-1699667 (hereinafter referred to as "Prior Art 1"). Prior Art 1 disclosed above describes a paper sensor that detects proline using a ninhydrin reaction, which allows for the immediate measurement of the effects of environmental stress in the field without transporting crops to a laboratory. However, existing paper-based multilayer sensors have technical issues. In Prior Art 1, the wax layer infiltrated into the paper dissolves as it reacts with chemicals such as ninhydrin solution or sulfosalicylic acid. This results in sample loss and a decrease in measurement sensitivity and resolution. In other words, the performance of the sensor deteriorates, making it difficult to accurately measure environmental stress. This poses a particular problem when the concentration of proline needs to be measured precisely. Therefore, there is a need for a new manufacturing process that can reduce sample loss and increase the sensitivity and resolution of the sensor during the process of detecting proline. FIG. 1 is a perspective view illustrating a diagnostic paper sensor according to an embodiment of the present invention. FIG. 2 is a drawing for explaining each layer of a diagnostic paper sensor according to an embodiment of the present invention. FIG. 3 is a plan view illustrating the pattern design process of a diagnostic paper sensor according to an embodiment of the present invention. FIG. 4 is a perspective view illustrating the process of folding a diagnostic paper sensor through an origami method according to an embodiment of the present invention. FIG. 5 is a flowchart for explaining a method for manufacturing a diagnostic paper sensor according to an embodiment of the present invention. FIGS. 6a, FIGS. 6b, FIGS. 6c, and FIGS. 6d are drawings for explaining a method for manufacturing a diagnostic paper sensor according to an embodiment of the present invention. Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals. In this specification and drawings (hereinafter referred to as the 'this specification'), red